diff --git a/src/pipeline.ts b/src/pipeline.ts
index 3255aa7..c85cc0b 100644
--- a/src/pipeline.ts
+++ b/src/pipeline.ts
@@ -35,6 +35,7 @@ async function handleEvent(event: DittoEvent, signal: AbortSignal): Promise<void
   }
   if (!(await verifyEventWorker(event))) return;
   if (encounterEvent(event)) return;
+  if (await existsInDB(event)) return;
   debug(`NostrEvent<${event.kind}> ${event.id}`);
 
   if (event.kind !== 24133) {
@@ -84,6 +85,13 @@ function encounterEvent(event: NostrEvent): boolean {
   return encountered;
 }
 
+/** Check if the event already exists in the database. */
+async function existsInDB(event: DittoEvent): Promise<boolean> {
+  const store = await Storages.db();
+  const events = await store.query([{ ids: [event.id], limit: 1 }]);
+  return events.length > 0;
+}
+
 /** Hydrate the event with the user, if applicable. */
 async function hydrateEvent(event: DittoEvent, signal: AbortSignal): Promise<void> {
   await hydrateEvents({ events: [event], store: await Storages.db(), signal });